Head mounted display systems are known that include a lens disposed between an eye of the user and the face of a display for projecting an enlarged virtual image of the displayed information. These systems, however, typically employ a lens with a simple curvature such as a spherical lens. The virtual image that results with the use of a spherical lens has a number of distortions, including variations in the magnification and field of curvature across the image as well as edge distortions such as barrel distortion. In order to compensate for such distortions compensating lenses and the like are typically added to the optical system. These additional optics, however, increase the weight and overall size of the optical system. It is important to minimize the weight and size of the optical system for a head mounted display unit, otherwise the unit is too heavy and cumbersome to be comfortably supported on a user's head.